1975 25 horse 2 stroke

[rpmdj1]

my 1975 evinrude 25 hrs timing

timing
ok when I was a kid if the timing was off the engine would turn over real hard is it the same with a 2 stroke out board and is it hard to check the timing

 

[F_R]

On motors of the type you mention, the timing varies with each time you change the throttle position. It ranges anywhere between full advance at Wide Open Throttle, and too retarded to run below slow idle. Those extremes are built in by design and not normally changeable. Not to be confused with timing of the breaker points' opening in relation to flywheel magnets position, which is adjusted by setting the points gap, either with a feeler gauge or the special tool timing fixture.

Neither of these is an issue with how hard it is to pull the starter cord when the throttle is set to the "Start" position.

 

[rpmdj1]

cool thank you
this only brings the question again why is it so hard to pull I have taken the plugs out to make sure the engine wasn't froze and it spins freely
I don't get it

 

[oldboat1]

Some time ago, I had a '50s 7 1/2 that was hard (stiff) to pull over, but ran very well once started. It felt very stiff -- smooth but stiff -- until there was some fuel flowing into the cylinders with repeated cranking (at least that was my sense). I don't know whether it was an issue with rings, or an internal problem -- didn't seem to have any running issues at all once fired up, so didn't check any further. Once started, is yours running well?

You could have a restriction under the flywheel -- driver coil could be binding against the flywheel, for example. If there is a restriction like that, you should be able to feel it by slowly turning the flywheel clockwise by hand. Good to do that while the plugs are still out -- and a good time to check compression too.

I take it, yours is a manual start only. (If you are talking about an electric start motor, maybe the issue is the starting circuit (low battery, poor connection, starter windings). If it spins easily with the plugs out, it's likely the starting system.)

 

[racerone]

Some of these motors have a special pulley in the recoil/---It is not round.---It is eliptical to make it easier to pull over on compression.---If it is not assembled correctly it can be hard to pull over.

 

[F_R]

If it pulls easy with the plugs out, I would have to guess there is nothing wrong with it. Let's face it, those 25hp motors got their horsepower mainly by high compression. Translated: You have to haul on the rope and follow through. Forget it if you have it mounted on a wobbly stand.

 

[rpmdj1]

Next Monday I will be buying the biggest marine battery that our local farm and fleet offers I hate fixing things by process of elimination but before I go any farther I have to repair or diagnose what I can comfortably do myself as I have found 1 marina in my area that's willing to look at because of its age and he charges 100.00 per hour but all theses suggestions gives me more avenues to look at so thank you all

 

[GA_Boater]

iboats carries manuals - http://www.iboats.com/Johnson-Outbo...2024196--session_id.726299082--view_id.251023

You might find a factory manual here - https://www.outboardbooks.com/

 

[rpmdj1]

update motor started

just post an update my motor is an 1975 25 horse had been sitting for about in my dads basement for roughly 15 years also I now have a manual
I bought my battery on Monday brought it home connected it and on the first turn of the key it beleched a big puff of smoke and was running idol was to fast but I couldn't find the adjuster although I did find an adjustment screw on the left side of the engine how ever when I turned it it
moved some mechanical stuff under the flywheel I think it has something to do with the points I shut it down but it would not start again so I waited an hour and tried it again it fired right up but again hi idol turned it off and had to wait before it would fire so I went out today turned the formentioned adjustment screw it woiuld fire then stall I hope by turning that screw I didn't break something
please keep in mind im a pretty good mechanic but this motor is brand new to me
I have pm'd another member

 

[Vic.S]

You are not running it with no water are you ? If so you have probably wrecked the water pump impeller .


You previous posts talk about getting a repair manual. I assume that is what you have..

What you need to get (from Outboardbooks.com ) is the Owners manual. It will explain how to operate it and what the various controls do

You say you are a "pretty good mechanic" so you should soon figure all this out OK. None of it is rocket science

 

[jbcurt00]

No need to start an Update topic, I combined it w 1 of your previous topics about this motor.

 

[oldboat1]

Post your model number, rpm. -- confirms year, features, and lets us talk the same language. Should be a plate on the top or side of the stern bracket -- that assembly for mounting it on the boat. So far, have not been able to follow the adjustments you describe.

 

[Vic.S]

No need to start an Update topic, I combined it w 1 of your previous topics about this motor.

It would be good if they were all combined into 1 thread!

 

[jbcurt00]

This was an 'update' so its a better fit as a continuation of the 1 topic.

The others, although about the same motor, all seem about specific queations or problems.

Motors, IMO, may also benefit from 1 single topic from a poorly running/non-op motor thru to relable good running motor, just like boat resto topics that address single aspects of a project rather then the boat repair from start to finish.

Many aspects of motor and boat repair overlap and run from 1 initial problem to another previously though unrelated problem. The discussions also tend to meander from whatever the initial post addressed to secondary concerns. Having it all together, IMO, helps the person seeking advice, those giving advice and others that come along after us w similar problems.

Not all of us want the info all together, for whatever reason, they prefer it separated and broken down into smaller pieces.

So for now, I'll leave them separate.

They could certainly be combined if rpm wants them condensed.

 

[rpmdj1]

im sorry I am new to postings and im not sure how to do certain operations on the forum but i am working on it
I have found a manual online here is the linkhttp://www.boatinfo.no/lib/evinrude/manuals/1973-1991johnsonevinrude.html#/0 I am on a very tight budget as im disabled and this manual is not the best I have found

 

[rpmdj1]

I don't know how to combine posts to create a thread

 

[jbcurt00]

If you decide you want the topics combined, just ssk, we can combine them. If you'd rather them separate, thats fine too. Up to you.

Only reason I merged the update, was for the reason I posted, not new topic, just an update.

I was speaking to Vics comment and my personal preference. How ever you want to split up the topics is fine.

 

[rpmdj1]

if I have offended anyone due to my innabilty to navigate this forum im sorry I had a stroke a year and a half ago and lost some cognitive thinking in other words when it comes to mechanics this motor would have been second nature now I have to reteach myself all over again I don't understand how to combine posts to make a thread and so many other things so please be patient

 

[Vic.S]

if I have offended anyone due to my innabilty to navigate this forum im sorry I had a stroke a year and a half ago and lost some cognitive thinking in other words when it comes to mechanics this motor would have been second nature now I have to reteach myself all over again I don't understand how to combine posts to make a thread and so many other things so please be patient

Don't worry about it ! Just found it a bit difficult to know what you were updating from that's all.

The manual you have found on boatinfo is not specific to the model ( its a Seloc manual I think)

The OEM manuals are specific to the model so much better and many times easier to use.

What you really need to begin with is the owners operating manual. If your dad bought the motor new he would have had the manual. Perhaps its still kicking around somewhere if he did
I am not sure about the screw you refer to but #84 in the diagram below is the idle speed setting screw. I guess that is it.

The throttle operates by moving the armature plate ( on which the points condensers and coils are mounted) below the fly wheel. A cam on the rim of this in turn operates the carb throttle valve via a roller mechanism on top of the intake manifold.

Check that as you operate the throttle control the valve in the carb moves from almost completely closed to fully open.

You may have to refer to the "sync and link" instructions in the repair manual but don't mess with any adjustments until you understand it all properly

 

[oldboat1]

per a PM I just received, rpmdj1's model number is 25552B. rpm -- think I recommended shop.evinrude.com for parts diagrams. Fairly easy to use, and worth a try. All have to be on the same page....